The aim of this study was the histopathological evaluation of apical and periapical tissues in dog teeth that were submitted to bacterial endotoxin, associated or not with calcium hydroxide. After removal of the pulp from 60 premolars, the teeth were divided into four groups and were filled with bacterial endotoxin (group 1), bacterial endotoxin plus calcium hydroxide (group 2), saline solution (group 3), or had induced periapical lesions with no treatment (group 4). After 30 days, animals were killed and the teeth processed histologically. The inflammatory infiltrate, the thickness of the periodontal ligament, and the presence of resorption areas were similar for groups 1 and 4. Groups 2 and 3 were similar to each other. It can be concluded that the bacterial endotoxin caused a periapical lesion and that calcium hydroxide detoxified the lipopolysaccharides in vivo.Improvement in microbiology techniques for culture and identification has shown that root canals in teeth with pulp necrosis and a chronic periapical reaction have a predominance of anaerobic microorganisms (1, 2), especially Gram-negative ones (3). This polybacterial infection is present not only in the lumen of the root canal and dentinal tubules, but also in the apical craters and the entire root canal system (2). Gram-negative microorganisms not only have different virulent factors and produce toxic products and sub-products in apical and periapical tissues, but also contain endotoxin in their cell wall. Endotoxin, which consists of lipopolysaccharides (LPS), is liberated during bacterial cell multiplication or death and is responsible for a series of important biological effects (4, 5). Its action on macrophages (6) triggers the release of a series of inflammatory, bioactive, chemical mediators, or cytokines (5), such as tumor necrosis factor (TNF) (4, 5) and interleukins-1 (5, 7), -6, and -8 (7). Endotoxin also induces fever (8), is mitogenic to B lymphocytes (5), activates the complement system (8) and the metabolism of arachidonic acid (5), and irreversibly adheres to mineralized tissues. These events lead to an inflammatory reaction and bone resorption in the periapical region. These facts emphasize the important role of LPS in the pathogenesis of periapical lesions (4, 9, 10, 11).A survey of the medical literature over the last 10 yr produced 22,450 articles dealing with endotoxin; however only four articles in dentistry (9, 10, 12, 13) evaluated the effects of LPS on apical and periapical tissues using experimental animals.Treatment of root canals in teeth with pulp necrosis and a chronic periapical reaction should not only be concerned with bacterial death, but also the inactivation of endotoxin. Safavi and Nichols (14, 15), Barthel et al. (4), and Olsen et al. (16) studied, in vitro, the effect of calcium hydroxide on bacterial LPS, because LPS may remain in the root canals between intracanal dressing sessions. However, there are no in vivo studies reporting this problem.The purpose of this study was to evaluate histopathologically the ef...

Coconut water was worse than milk in maintaining human fibroblast cell viability.

RESUMOObjetivo: Apresentar revisão de literatura sobre dentes natais e neonatais, abordando características clínicas, fatores etiológicos, medidas terapêuticas e a importância do conhecimento desta anomalia, por odontopediatras e pediatras. Fontes de dados:Foram selecionados os artigos mais relevantes sobre o tema, desde 1950 até 2006, pesquisados no Medline e na Bibliografia Brasileira em Odontologia (BBO), além de livros de pertinentes.Síntese dos dados: Os dentes natais e neonatais consistem em uma anomalia de erupção, sendo caracterizados por seu irrompimento na cavidade oral durante o período intra-uterino ou no primeiro mês de vida respectivamente, podendo fazer parte da dentição decídua normal ou supranumerária. Esses dentes, em geral, apresentam bordos cortantes e podem estar relacionados ao aparecimento de ulcerações na base da língua do bebê e/ou no seio materno, comprometendo a amamentação. A fraca implantação óssea desses dentes favorece sua grande mobilidade, tornando-se, assim, um fator de risco à sua aspiração ou deglutição pela criança. A abordagem terapêutica depende da dentição à qual pertence o dente e dos possíveis problemas que este pode causar à saúde da criança ou da mãe.Conclusões: O conhecimento sobre as características clínicas e os possíveis distúrbios aos quais os dentes natais e neonatais estão relacionados por odontopediatras e pediatras possibilita a interação necessária para o diagnóstico precoce e a abordagem integral da criança.Palavras-chave: dente decíduo; dentes natais; Odontopediatria; Pediatria. AbStRActObjective: To review available data about natal and neonatal teeth, emphasizing clinical characteristics, etiological factors, treatment, and the importance of the knowledge about this anomaly by pediatric dentists and pediatricians.Data sources: The most relevant articles published on the subject were selected, from 1950 to 2006, browsed on Medline, Brazilian Bibliografy of Odontology (BBO) and Dentistry books.Data synthesis: Natal and neonatal teeth are considered eruption anomalies, characterized by eruption into oral cavity during the intrauterine period or during the first month after birth, respectively, being part of the regular deciduous or the supernumerary dentitions. As these teeth usually present cutting edges, they can be related to traumatic injury to newborn's tongue and/or to mother's nipples, compromising breastfeeding. In general, the weak attachment of these teeth to alveolar bone favors a high degree of mobility, which exposes the infant to the risk of aspiration or swallowing them. The management depends on which dentition these teeth belong and/or on complications that may affect either infant's or mother's health.Conclusions: The knowledge about the clinical characteristics and the possible complications related to natal and neonatal teeth by pediatric dentists and pediatricians provides the necessary interaction to early diagnosis and infant general management. Key